1. Field of the Invention
The present invention relates to a recording apparatus which is usable in a printer, a digital copying apparatus, or a facsimile device, for recording a desired image or character on a recording paper. More particularly, the present invention relates to a recording apparatus which is useful for precisely recording a color image and character.
2. Description of the Prior Art
Recently, as an image recording system for use with a printer, a thermal transfer recording system using a thermal head and a ink sheet has been available in the market. Such a system is disclosed in, for example Japanese Laid-Open Patent Publication No. 62-47717 and Japanese Laid-Open Patent Publication No. 63-50198.
An example of a conventional recording apparatus using such a thermal transfer recording system is described below.
FIG. 10 illustrates a sectional structural diagram of the conventional recording apparatus. The reference numeral 101 designates a thermal head incorporating a plurality of resistive heating elements 109 which are arranged in the widthwise direction of recording paper 103. The reference numeral 104 designates an ink sheet made of a film substrate coated with thermally soluble or softening ink (hereinafter called thermally soluble ink) over the upper surface thereof. The thermal head 101 is pressed against a platen 102, and the ink coated surface of the ink sheet 104 faces the recording paper 103. In this condition, by causing the platen 102, the recording paper 103, and the ink sheet 104 to move in the direction of the illustrated arrows, the resistive heating elements 109 generate heat according to a recording signal so as to melt or soften (hereinafter simply melt) the ink opposing the resistive heating elements 109. Then, the ink sheet 104 is separated from the recording paper 103 to form an ink image 105 on the recording paper 103.
However, with the conventional recording apparatus having the above structure, ink cannot properly adhere to a recording paper which has insufficient superficial smoothness. This in turn results in a poor image quality since the ink often drops from the recording paper 103. In particular, when performing the color-super-imposed image recording in the manner proposed by Japanese Laid-Open Patent Publication No. 63-50198, since the ink itself generates concave and convex surface structures, a color super-imposed on preceding colors cannot be easily deposited on the recording paper. Furthermore, the recording paper easily displaces itself, and thus, perfect matching of a color position can hardly be carried out by the conventional recording apparatus.
To improve the image recording characteristics when using normal recording paper, there is a method of repeating the transfer of the ink image on the recording paper after once forming an ink image on an intermediate transfer medium, as was proposed by Japanese Laid-Open Patent Publication No. 59-16932. Nevertheless, the ink cannot be fully transferred from the intermediate transfer medium onto the recording paper, thereby causing residual ink to remain on the intermediate transfer medium, and as a result, it is necessary to clean the intermediate transfer medium.